LED array module
The invention describes a light emitting diode array module ( 30 ) comprising a plurality of light emitting diode structures ( 10 a, 10 b ), wherein the light emitting diode structures ( 10 a, 10 b ) are arranged such that there is an optical cross talk between the light emitting diode structures ( 10 a, 10 b ) during operation of the light emitting diode array module ( 30 ), wherein at least a first light emitting diode structure ( 10 a ) of the plurality of light emitting diode structures ( 10 a, 10 b ) is characterized by a first color, and wherein at least a second light emitting diode structure ( 10 b ) of the plurality of light emitting diode structures ( 10 a, 10 b ) is characterized by a second color different than the first color, wherein the first color, the second color and the optical cross talk between the light emitting diodes are arranged to provide a predefined light distribution in a reference plane ( 40 ) perpendicular to an optical axis ( 50 ) of the light emitting diode an-ay module ( 30 ). The invention further describes a lighting device comprising one or more LED array modules ( 30 ).
1. An apparatus, comprising:
a plurality of light-emitting diodes (LEDs) arranged as an LED array,
the plurality of LEDs being distributed between a central group of LEDs and a border group of LEDs that surrounds the central group of LEDs,
the central group of LEDs being arranged in a two-dimensional subarray,
the central group of LEDs including central blue LEDs that are configured to emit central blue light and central yellow LEDs that are configured to emit central yellow light such that, when observed at a reference plane separated from the LED array, the central blue light and the central yellow light combine to appear as central white light having a central correlated color temperature, and
the border group of LEDs including border blue LEDs that are configured to emit border blue light and border yellow LEDs that are configured to emit border yellow light such that, when observed at the reference plane, the border blue light and the border yellow light combine to appear as border white light having a border correlated color temperature that is different from the central correlated color temperature.
2. The apparatus of claim 1 , wherein:
the central blue LEDs and the central yellow LEDs are arranged in a checkerboard pattern in the LED array; and
the border blue LEDs and the border yellow LEDs are arranged in a checkerboard pattern in the LED array.
3. The apparatus of claim 1 , wherein:
each of the central blue LEDs is configured to emit light having a same central blue intensity;
each of the central yellow LEDs is configured to emit light having a same central yellow intensity;
each of the border blue LEDs is configured to emit light having a same border blue intensity;
each of the border yellow LEDs is configured to emit light having a same border yellow intensity; and
a ratio of the central blue intensity to the central yellow intensity differs from a ratio of the border blue intensity to the border yellow intensity.
4. The apparatus of claim 1 , wherein:
each LED in the central group is fully surrounded by adjacent LEDs in the LED array; and
each LED in the border group is only partially surrounded by adjacent LEDs in the LED array.
5. The apparatus of claim 1 , wherein:
the array of LEDs is a two-dimensional rectilinear array;
each LED in the central group is surrounded by four directly adjacent LEDs and four diagonally adjacent LEDs in the LED array; and
each LED in the border group is surrounded by fewer than four directly adjacent LEDs or fewer than four diagonally adjacent LEDs in the LED array.
6. The apparatus of claim 1 , wherein:
the LED array is a two-dimensional array that extends in a first plane that is generally parallel to the reference plane;
each LED in the array is configured to emit light from a first emission surface oriented generally parallel to the first plane and from at least one second emission surface oriented substantially orthogonal to the first emission surface; and
the LEDs of the array are arranged such that the at least one second emission surface of an LED is positioned to receive light from a second emission surface of at least another LED in the array.
7. The apparatus of claim 6 , wherein light emitted from a second emission surface of a first LED of the array is configured to interact with a phosphor of a second LED of the array.
8. The apparatus of claim 6 , wherein central blue light emitted from a second emission surface of a first central blue LED is configured to be absorbed by a phosphor of a first central yellow LED.
9. The apparatus of claim 6 , wherein central blue light emitted from a second emission surface of a first central blue LED is configured to be absorbed by a phosphor of a first border yellow LED.
10. The apparatus of claim 6 , wherein border blue light emitted from a second emission surface of a first border blue LED is configured to be absorbed by a phosphor of a first border yellow LED.
11. The apparatus of claim 6 , wherein border blue light emitted from a second emission surface of a first border blue LED is configured to be absorbed by a phosphor of a first central yellow LED.
12. A method for providing light, comprising:
electrically powering a plurality of light-emitting diode (LEDs) arranged as an LED array, the plurality of LEDs being distributed between a central group of LEDs and a border group of LEDs that surrounds the central group of LEDs, the central group of LEDs being arranged in a two-dimensional subarray, the central group of LEDs including central blue LEDs and central yellow LEDs, the border group of LEDs including border blue LEDs and border yellow LEDs;
emitting central blue light from the central blue LEDs;
emitting central yellow light from the central yellow LEDs such that, when observed at a reference plane separated from the LED array, the central blue light and the central yellow light combine to appear as central white light having a central correlated color temperature;
emitting border blue light from the border blue LEDs; and
emitting border yellow light from the border yellow LEDs such that, when observed at the reference plane, the border blue light and the border yellow light combine to appear as border white light having a border correlated color temperature that is different than the central correlated color temperature.
13. The method of claim 12 , wherein:
the central blue LEDs and the central yellow LEDs are arranged in a checkerboard pattern in the LED array; and
the border blue LEDs and the border yellow LEDs are arranged in a checkerboard pattern in the LED array.
14. The method of claim 12 , wherein:
the central blue LEDs emit light having a same central blue intensity;
the central yellow LEDs emit light having a same central yellow intensity;
the border blue LEDs emit light having a same border blue intensity;
the border yellow LEDs emit light having a same border yellow intensity; and
a ratio of the central blue intensity to the central yellow intensity differs from a ratio of the border blue intensity to the border yellow intensity.
15. The method of claim 12 , wherein at least some of the LEDs of the LED array are monolithic devices disposed on a single substrate.
16. The method of claim 12 , wherein:
each LED in the central group is fully surrounded by adjacent LEDs in the LED array; and
each LED in the border group is only partially surrounded by adjacent LEDs in the LED array.
17. The method of claim 12 , wherein:
the array of LEDs is a two-dimensional rectilinear array;
each LED in the central group is surrounded by four directly adjacent LEDs and four diagonally adjacent LEDs in the LED array; and
each LED in the border group is surrounded by fewer than four directly adjacent LEDs or fewer than four diagonally adjacent LEDs in the LED array.
18. An apparatus, comprising:
a plurality of light-emitting diode (LEDs) arranged as a two-dimensional rectilinear LED array,
the plurality of LEDs being distributed between a central group of LEDs and a border group of LEDs that surrounds the central group of LEDs, the central group of LEDs being arranged in a two-dimensional subarray, each LED in the central group being surrounded by four directly adjacent LEDs and four diagonally adjacent LEDs in the LED array, each LED in the border group being surrounded by fewer than four directly adjacent LEDs or fewer than four diagonally adjacent LEDs in the LED array,
the central group of LEDs including central blue LEDs that are configured to emit central blue light and central yellow LEDs that are configured to emit central yellow light such that, when observed at a reference plane separated from the LED array, the central blue light and the central yellow light combine to appear as central white light having a central correlated color temperature, the central blue LEDs and the central yellow LEDs being arranged in a checkerboard pattern in the LED array, and
the border group of LEDs including border blue LEDs that are configured to emit border blue light and border yellow LEDs that are configured to emit border yellow light such that, when observed at the reference plane, the border blue light and the border yellow light combine to appear as border white light having a border correlated color temperature that is different than the central correlated color temperature, the border blue LEDs and the border yellow LEDs are arranged in a checkerboard pattern in the LED array.
19. The apparatus of claim 18 , wherein:
the LED array is a two-dimensional array that extends in a first plane that is generally parallel to the reference plane;
each LED in the array is configured to emit light from a first emission surface oriented generally parallel to the first plane and from at least one second emission surface oriented substantially orthogonal to the first emission surface;
the LEDs of the array are arranged such that the at least one second emission surface of an LED is positioned to receive light from a second emission surface of at least another LED in the array;
light emitted from a second emission surface of a first LED of the array is configured to interact with a phosphor of a second LED of the array;
central blue light emitted from a second emission surface of a first central blue LED is configured to be absorbed by a phosphor of a first central yellow LED;
central blue light emitted from a second emission surface of a first central blue LED is configured to be absorbed by a phosphor of a first border yellow LED;
border blue light emitted from a second emission surface of a first border blue LED is configured to be absorbed by a phosphor of a first border yellow LED; and
border blue light emitted from a second emission surface of a first border blue LED is configured to be absorbed by a phosphor of a first central yellow LED.